Cylinder combustion performance monitoring and control with coordinated torque control

Abstract

An engine control system includes a disturbance module, a torque correction module, a torque-to-spark module, and a spark correction module. The disturbance module determines a disturbance value for a past combustion stroke of a cylinder of an engine based on rotation of a crankshaft. The torque correction module selectively determines a torque correction for a future combustion stroke of the cylinder based on the disturbance value. The torque-to-spark module determines a spark correction based on the torque correction and determines an uncorrected spark timing based on a torque request. The spark correction module determines a corrected spark timing based on the uncorrected spark timing and the spark correction and generates spark during the future combustion stroke based on the corrected spark timing.

1. An engine control system comprising:
 a disturbance module that determines a disturbance value for a past combustion stroke of a cylinder of an engine based on rotation of a crankshaft; 
 a torque correction module that selectively determines a torque correction for a future combustion stroke of the cylinder based on the disturbance value; 
 a torque-to-spark module that determines a spark correction based on the torque correction and that determines an uncorrected spark timing based on a torque request; and 
 a spark correction module that determines a corrected spark timing based on the uncorrected spark timing and the spark correction and that generates spark during the future combustion stroke based on the corrected spark timing. 
 
     
     
       2. The engine control system of  claim 1  wherein the torque-to-spark module determines the spark correction further based on the torque request. 
     
     
       3. The engine control system of  claim 2  wherein the torque-to-spark module determines the spark correction based on a relationship between torque and spark timing. 
     
     
       4. The engine control system of  claim 1  wherein the torque-to-spark module determines a second torque request based on the torque correction and the torque request, determines an absolute spark timing based on the second torque request, and determines the spark correction based on a difference between the absolute spark timing and the uncorrected spark timing. 
     
     
       5. The engine control system of  claim 4  further comprising a security module that determines a redundant spark correction based on the torque correction and the torque request and that selectively adjusts the spark correction based on a comparison of the spark correction and the redundant spark correction. 
     
     
       6. The engine control system of  claim 5  wherein the security module sets the spark correction to a previous spark correction when a difference between the spark correction and the redundant spark correction is greater than a predetermined amount. 
     
     
       7. The engine control system of  claim 5  wherein the security module determines a second redundant torque request based on the torque correction and the torque request, determines a second absolute spark timing based on the second redundant torque request, and determines the redundant spark correction based on a difference between the second absolute spark timing and the uncorrected spark timing. 
     
     
       8. The engine control system of  claim 1  wherein the torque correction module determines other torque corrections for other cylinders of the engine, respectively, and verifies that a sum of the torque correction and the other torque corrections is within a predetermined range centered at zero. 
     
     
       9. The engine control system of  claim 8  wherein the spark correction module determines other spark corrections for the other cylinders of the engine based on the other torque corrections, respectively, and generates spark during other future combustion strokes of the other cylinders based on the other spark corrections, respectively. 
     
     
       10. The engine control system of  claim 1  wherein the spark correction module determines the corrected spark timing based on a sum of the uncorrected spark timing and the spark correction. 
     
     
       11. An engine control method comprising:
 determining a disturbance value for a past combustion stroke of a cylinder of an engine based on rotation of a crankshaft; 
 selectively determining a torque correction for a future combustion stroke of the cylinder based on the disturbance value; 
 determining a spark correction based on the torque correction; 
 determining an uncorrected spark timing based on a torque request; 
 determining a corrected spark timing based on the uncorrected spark timing; and 
 generating spark during the future combustion stroke based on the corrected spark timing. 
 
     
     
       12. The engine control method of  claim 11  further comprising determining the spark correction further based on the torque request. 
     
     
       13. The engine control method of  claim 12  further comprising determining the spark correction based on a relationship between torque and spark timing. 
     
     
       14. The engine control method of  claim 11  further comprising:
 determining a second torque request based on the torque correction and the torque request; 
 determining an absolute spark timing based on the second torque request; and 
 determining the spark correction based on a difference between the absolute spark timing and the uncorrected spark timing. 
 
     
     
       15. The engine control method of  claim 14  further comprising:
 determining a redundant spark correction based on the torque correction and the torque request; and 
 selectively adjusting the spark correction based on a comparison of the spark correction and the redundant spark correction. 
 
     
     
       16. The engine control method of  claim 15  further comprising setting the spark correction to a previous spark correction when a difference between the spark correction and the redundant spark correction is greater than a predetermined amount. 
     
     
       17. The engine control method of  claim 15  further comprising:
 determining a second redundant torque request based on the torque correction and the torque request; 
 determining a second absolute spark timing based on the second redundant torque request; and 
 determining the redundant spark correction based on a difference between the second absolute spark timing and the uncorrected spark timing. 
 
     
     
       18. The engine control method of  claim 11  further comprising:
 determining other torque corrections for other cylinders of the engine, respectively; and 
 verifying that a sum of the torque correction and the other torque corrections is within a predetermined range centered at zero. 
 
     
     
       19. The engine control method of  claim 18  further comprising:
 determining other spark corrections for the other cylinders of the engine based on the other torque corrections, respectively; and 
 generating spark during other future combustion strokes of the other cylinders based on the other spark corrections, respectively. 
 
     
     
       20. The engine control method of  claim 11  further comprising determining the corrected spark timing based on a sum of the uncorrected spark timing and the spark correction.